Method of sizing carbonate filled paper



Patented May 5, 1931 UNITED STATES HAROLD Par-Eur OFFICE aoanar narrow, or: LawaENqE, msacnusmrs assmnon 'ro aurora process com'oaa'rmma eoarona'rron or massaonusn'r'rs mirrnonor sizme caa'aona'm rnmnn rarer.

11o Drawing.

This invention'relates to a method of sizing paper and more particularly to a method of 'sizinggpaper filled with carbonate filler.

The princlpal object of this invention is to provide a method of sizing paper filled with carbonate filler wherein previously mixed sizing is added to the paper mix at the wet end of the aper machine.

Other ob acts and advantages of this invention wiil become apparent during the course of the following description.

As is known, when rosin size and alum are added in the beater, mixer, or the like to fibrous material, and carbonate filler is then added, the sizing eifect of the rosin size and .alum is materially deteriorated, sometimes even to the point of destruction, by the carbonate filler before the pa er mix passes on to a web-formin device 0 a paper machine with the result t at the finished paper made from such a mix is incompletely sized, or, v

easily incorporated when added to the stock in some cases, substantially unsized.

. I have discovered that it is possible to avoid this deterioration or destruction of the sizing by mixing rosin size and alum, both preferably in dilute solutions, in a separate container and adding the resultin product, preferably continuously to the fiirous mix containing carbonate l paper machine.

In the preferred practice of my process I mix in a se arate container rosin size with an excess 0 alum. The fprecipitatemay be separated as by filtration rom the precipitating bath and used in this condition, or it may bedried and employed in the dried condition aftersuitable comminution, but these procedures are unnecessa as the soluble by-prodnets of the rosin size-alumreaction do not appear to be detrimental in the process. The

precipitate, therefore, together with the accompan 'ing' lixfid in the separate container is adds, to the brous mix containing carbonate fillerpreferably continuously at the wet end of the paper machine. However in view of the fact that it is somewhat difiicult to disperse flocks of sizing and to distribute them properl in the paper mix to give a substantial y um fo rm sizi' efl'ect', I prefer to pass the precipitated sizing prior to its adler at the wet end of the teriorated'even to the point 0 Application filed September 15,1928. Serial in. 304,175.

dition tothe fibrous mix through a dispersing or disintegrating machine such as a colloidmill.

- In one modification of my process I have found it advantageous to efiect the mixing of rosin size and alum in the presenceof other material which may be insoluble, such as fibre or clay, or in the presence of material which may be soluble, preferably colloidally soluble, such as starch or glue. In such a modification, the resulting mix is added, as in the previous instance, to the fibrous stock containing carbonate filler at the-wet end of the paper machine. When rosin size and alum are. mixed in this manner, the sizing,

material resulting therefrom is produce either in a form ,which renders it readily dispersible, as when fibre or cla is used, or in a form which is more finel ispersed as when starch or glue is used. n either event the result is that the mix is thus much more at the-wet end of the paper machine.

By adding the sizing mlxture to the fibrous mix containing carbonate filler at the wet end of, the paper machine, the previously mixed sizing is thus added at a point where there will be a. minimum of intimacy and time of contact of the constituents of the mix before the web is formed. This is necessary as I have found that if the sizin mixture be added when the fibrous mix is in relatively concentrated condition,- andparticularly when the relatively concentrated mix is subjected to agitation as is normal in stock chests, the sizing efi'ect is'vergy guickly destruction. The sizing effect even when the mix is in the diluted condition is gradually deteriorated, but is substantially unalfected within the time limits that the mix is maintained in the dilute state in the usual papermaking procedure. Moreover, although agl- I tation in the dilute state hastens to a certai'nextent the deterioration of the sizing of feet, the speed of deterioration is not nearl so pronounced as in the concentratedcond tion, and from a practical standpointI have found that the itation to which the diluted mix is subjects prior .to deliveryonto the mplete dey welyforming device does not deteriorate the sizing effect to a. substantial degree.

An illustrative furnish suitable for use in the practice of my process is as follows:

Materials added in beater Fibrous furnish, e. gosul Carbonate tiller, 0. g. ca

Pounds phite and soda pulps 1700 cium carbonate magnesium hydroxide 300 Materials mined in separate container and added proportionately and continuously on dilution Pounds Size, e. g. rosin size 120 Size precipitant, e. g. alum 180 Another illustrative furnish is as follows:

Materials added in the beater Pounds Pounds Fibre, e. g. sulphite and soda pnlps 240 Size, e. 3. main size 120 Size precipitant, e, g. alum 180 In the above formulae, the weights of size and carbonate filler refer to the bone dry basis, the weights of all other ingredients being given on the air d basis.

The herein described method of sizing may be used alone for producing a sized carbonate filled paper or the method may be used in connection with the methods of sizing paper disclosed in my copending applications Serial No. 262,030.. filed March 15, 1928; Serial No. 304,167, filed Sept. 5, 1928; Serial No. 304,168, filed Sept. 5, 1928; Serial No. 304,170, filed Sept. 5 1928; Serial No. 304,172, filed Sept. 5, 1928; Serial No. 304.173, filed Sept. 5, 1928; Serial No. 304,176, filed Sept. 5, 1928; Serial No. 304.17 7 filed Sept. 5, 1928.

Of course instead of mixing the rosin size and alum in a separate containenstreams of these materials may be so placed as to impinge on one another and the resultant stream be directed into the paper nix at the wet end of the paper machine. his procedure offers no special advantage; as a matter of fact, the mixin of the size and alum is apt to be less comp etc under this condition than when a separate container is used. Therefore I consider this variation the substantial equivalent of mixing the size and alum in a. separate container.

In place of alum as a size precipitant I may use with a. measure of success an acid suc as sulphuric acid (H SOJ, an acid salt such as sodium bisulfate (NaHSOQ or a salt of a trivalent metal, such as ferric iron or the'other-salts of aluminum. Of the aluminum salts available I may use the chloride or the like, but I prefer to use ordinary alum.

In place of rosin size I may use satisfactorily in the practice of my process other sizes, for example, soaps, such as the oleates, or any other size derived by treatment with an alkaline substance or the like from maw terial originally of acid characteristics or from other material which likewise is of a partially or completely saponifiable nature, such as saponified beeswax.

By the term carbonate filler as employed herein, is intended to be i11clu(ledcalciu1n carbonate, of which lime mud from the cansticizing process in one form; calcium carbonate magnesium basic carbonate employed in the paper disclosed in my U. S. Patent No. 1,595,416; calcium carbonate magnesium hydroxide disclosed in my U. S. Patent No. 1,415,391; or other substantially water insoluble normal or basic carbonates of alkaline earth metals (which expression is herein intended to inc ude magnesium), orcompounds, double salts, or physically associated mixtures of these with one or more acid soluble materials of a substantially water insoluble nature. The term carbonate filler is also intended to include fibrous material and/or other material such as paper coating constituents or the like containln one or more compounds of the character re erred to, such as old pa ers "or similar papers, broke, or the li e.

By the term wet end of the paper machine is intended to be included those instrumentalities em loyed in paper manufacture by which an /or in which a relatively concentrated paper mix is diluted, and treated, conveyed or fed up to the point of web formation, such as the mixing box, regulating and proportioning devices, rifllers, troughs, screens, head boxes, inlets, and the like, including also instrumentalities used in the white water cycle.

When I use the term rosin size it is to be understood that I mean to include any material produced by the action of alkali, generally in aqueous solution, on rosin, or on matural or synthetic resin acid or acids, regardless of the exact composition of the product or the varying composition which different samples may possess.

When I use the word paper herein, I use it in the broad sense to include products of manufacture of all types and of all weights and thicknesses, which contain as an essential constituent a. considerable amount of prepared fiber and which are capable of being produced on a. Fourdrinier, cylinder, or other forming, felting, shaping or molding machine.

lVhile .have described in detail the preferred e odiment of my invention, it is to be understood that the details of procedure, the proportions of ingredients, and the arrangement of steps may-be widely varied without departing from the s irit of the irvention or the scope of the su joined claim I claim:

1. The method of sizing paper filled with carbonate filler comprising separately mixing size and size precipltant, and mixing the resulting productwith fibrous material and carbonate filler under conditions favoring the minimizing of the time of contact of the con stituents of the mix, and thereafter making paper therefrom. l

2. The method of sizing paper filled with carbonate filler comprising separatel mixing size and excess of size precipitant, mixing the resulting product with fibrous material and carbonate filler under conditions favoring the minimizing of the time of contact of the con- 7 stituents of the mix, and thereafter making paper therefrom. w

3. The method of sizing paper filled with carbonate filler comprising separately mixing size and size precipitant, and mixing the resulting product with fibrous material and carbonate filler under conditions favoring the minimizing of the intimacy and time of contact of the constituents of the mix, and thereafter making paper therefrom.

4. The method of sizing paper filled with carbonate filler comprising separately mixing size and size precipitant, and mixing the resulting product with fibrous material and carbonate filler at the wet end of the paper machine.

5. The method of sizing paper filled with carbonate filler comprising separately mixing saponified material and precipitant therefor, and mixing the resulting product with fibrous material and carbonate filler at the wet end of the paper machine.

6. The method of sizing paper filled with carbonate filler comprising separately mixing size and a salt of a trivalent metal, and mixing the resulting product with fibrous material and carbonate filler at the wet end of the paper machine.

7. The method of sizing paper filled with carbonate filler comprising separately mixing rosin size and size precipitant, and mixing the resulting productwith fibrous material and carbonate filler at the wet end of thepaper machine. i

8. The method of sizing paper filledwith carbonate filler comprising separately mixing size and a salt of aluminum, and mixing the resulting product with fibrous material and carbonate filler at the wet end of the paper machine.

9. The method of sizing paper filled with carbonate filler comprising separately mixing size and alum, and mixing the resulting product with fibrous material and carbonate filler at the wet end of the paper machine.

10. The method of sizing paper filled with carbonate filler comprising separately mixing rosin size and alum, and mixing the resulting product with fibrous material and carbonate filler at the wet end of the paper machine.

11. The method of sizing paper filled with carbonate filler comprising separately mixing rosin size and excess of alum, and mixing the resulting product with fibrous material and carbonate filler at the wet end of the paper machine. p

12. The method of sizing paper filled with carbonate filler comprising separately mixing size and size precipitant, finely dispersing the resulting product, and mixing the finely dispersed product with fibrous material and carbonate filler at the Wet end of the paper machine.

13. The method of sizing paper filled with carbonate filler comprising separately mixing size and alum, finely dispersing the resulting product, and mixing the finely dis rsed product with fibrous material and car onate filler at the wet end of the paper machine.

14. The method of sizing paper filled with carbonate filler comprising separately mixing rosin size and size precipitant, finely dispersing the resulting product, and mixing the finely dispersed product with fibrous material and carbonate filler at the wet end of the paper machine.

15. The method of sizing paper filled with carbonate filler comprising separately mixing rosin size and alum, finely dispersing the resulting product, and mixing the finely dispersed product with fibrous material and carbonate filler at the wet end of the paper machine.

16. The method of sizing paper filled with carbonate filler comprising separately mixing size and size precipitant in the presence of other material, and mixing the resulting product to a fibrous material and carbonate filler at the wet end of the paper machine.

17. The method of sizing paper filled with carbonate filler comprising separately mixing size and size precipitant in the presence of colloidal material, and mixing the resulting product with fibrous material and carbonate filler at the wet end of the paper machine.

18. The method of sizing paper filled with carbonate filler comprising separately mixing size and size precipitant in the presence of colloidally soluble material, and mixing the resulting product with fibrous material and carbonate filler at the wet end of the paper machine.

19. The method of sizing paper filled with carbonate filler comprising separately mixing size and size precipitant in the presence of starch, and mixing the resulting product with fibrous material and carbonate filler at the wet end of the paper machine.

20. The method of sizing paper filled with carbonate filler comprising separately mixing rosin size and alum in the presence of starch, and mixing the resulting product with fibrous material and carbonate filler a the wet end of the paper machine.

III;-

21. In a process of the character described the step of mixing with fibrous material and carbonate filler the insoluble reaction prodnet of size and size precipitant at the wet end of the paper machine.

22. In a process of the character described the step of mixing with fibrous material and carbonate filler the insoluble reaction product of saponified material and a precipitant therefor at the wet end of the paper machine.

23. In a process of the character described the step of mixing with fibrous material and carbonate filler the insoluble reaction prodnot of rosin size and alum at the wet end of the paper machine.

In testimony whereof I afiix my signature.

HAROLD ROBERT RAFTON.

21. In a process of the character described the step of mixing with fibrous material and carbonate filler the insoluble reaction prodnot of size and size precipitant at the wet end 5 of the paper machine.

22. In a process of the character described the step of mixing with fibrous material and carbonate filler the insoluble reaction product of saponified material and a precipitant 10 therefor at the wet end of the paper machine.

23. In a process of the character described the step of mixing with fibrous material and carbonate filler the insoluble reaction prod- 15 uct of rosin size and alum at the wet end of the paper machine.

In testimony whereof I affix my signature.

HAROLD ROBERT RAFTON.

CERTIFICATE OF CORRECTION.

Patent No. 1,803,650. Granted May 5, 1931, to

HAROLD ROBERT RAFTON.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, line 77, for the word "in" read is; page 3, line 103, claim 16, for "to a" read with; and that the said Letters Patent should he read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 11th day of August, A. D. 1931.

Wm. A. Kinnan, (Seal) Acting Commissioner of Patents.

CERTIFICATE OF CORRECTION.

Patent No. l,803,650. Granted May 5, 1931, to

HAROLD ROBERT RAFTON.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, line 77, for the word "in" read is; page 3, line 103, claim 16, for "to a" read with; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 11th day of August, A. D. 1931.

Wm. A. Kinnan, (Seal) Acting Commissioner of Patents. 

